Transcript UNIT V File
Geographic Information System (GIS) Submitted by M .U. Kale Assistant professor Irrigation & Drainage Engineering Dr. P.D.K.V. Akola Geographic Information System (GIS) A Geographic Information System (GIS) can be defined as a computer-based system for the digital entry, storage, transformation, analysis, and display of spatial data. Fundamentals of GIS. • Database Query: select various combinations of variables for examination • Queries are of two types I. queries of location (What occurs in this location?) II. queries of attribute (Where are the areas in which attribute occurs?) • Derivative Mapping we combine selected components of our database to yield new derivative layers. • Process Modeling It is a third area that is receiving increasing attention -- process or simulation modeling. Components of GIS Application and need of GIS • GIS is one of many tools that may be used to solve problems • The decision about whether to use a GIS is complex. • GIS results efficiency. in appropriateness and Introduction to arc view GIS • Most popular desktop GIS analysis and map presentation software package. • Create intelligent, dynamic maps using data from numerous sources. • Includes tools and data. • We can use out-of the- box to perform state-of-the-art analysis on key issues. Main features of Arc View • It can access and link documents, images, tables, text, graphics, spreadsheets, maps, multimedia, and CAD drawings in an integrated and comprehensive way. • It provides routine display and plotting of collection system maps and querying the GIS database. • Helps to quickly select and display different combinations of data for creative visualization of mapping data. Main features of Arc View • Directly use AutoCAD drawings (DWG files) or AutoCAD interchange files (DXF files). • Link map information to SQL databases which are common in local governments, such as: ORACLE, INGRES, INFORMIX, and SYGIS data can be explored and retrieved by selecting features or formulating logical expressions. • GIS BSE Arc View provides editing tools for creating new maps and modifying existing ones. • Arc View is very user-friendly and provides context sensitive on-line help Limitations • A limitation of Arc View is that it is not intended to support a GIS production shop. • The paper maps cannot be digitized directly in Arc View. • Arc View has limited feature editing capability Decision support system • Decision support systems (DSS) are developed to assist decision-makers. • Decision support systems are like the central nervous system connecting the operational entities to the brain. Components of DSS • Access to data and data output (maps, reports) • Access to GIS analysis (e.g. overlay and proximity analysis) • Access to models or rule-based "expert" information • Methods to account for and display error and uncertainty • Logging and tracking methods to document the decision process • Methods to evaluate alternative scenarios / trade-offs. Spatial Decision Support System (SDSS) • SDSS is an interactive, computer-based system designed to support a user or group of users in achieving a higher effectiveness of decision making while solving a semi-structured spatial decision problem Principles of SDSS • The DDM paradigm - the technology for a DSS must consist of three sets of capabilities in the areas of dialog, data, and modeling (the DDM paradigm) (Sprague and Watson, 1996); • A well-design SDSS should have balance among the three capabilities. Components of SDSS Functions of SDSS • The Data Base Management System (DBMS) contains the functions to manage the geographic data base; • The Model Base Management System (MBMS) contains the functions to manage the model base; • The Dialog Generation and Management System (DGMS) manages the interface between the user and the rest of the system. Thank you!